下面是来自openCV文档的简单代码,用于打开和关闭摄像头,
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
# Our operations on the frame come here
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
# Display the resulting frame
cv2.imshow('frame',gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
问题:
1)上面的代码中使用numpy库是什么,为什么需要它?
2)如何查看cv2.waitKey(0)
的返回值?
答案 0 :(得分:4)
cv2
并存)。Python: cv.WaitKey(delay=0) → int
Doc ...只需使用函数中的常规赋值cap.release()
See example here